This invention relates generally to a method of detecting turbulence in laminar air flow. While the invention will find many applications, it is particularly useful in detecting turbulence in a clean room in which a vertical or horizontal laminar flow of air is introduced into the room in order to sweep contaminating particles from the room.
Present day contamination standards in clean rooms are highly exacting and, in some instances, it is necessary that each cubic foot of air in the room contain less than ten contamination particles of a size of one micron or less. In order to meet such standards, it is essential to keep the flow of air through the room in the most nearly achievable laminar state. Turbulence in the stream creates vortexes which entrap particles and cause them to contaminate the work or process in the room.
Unless the room is completely empty, it is virtually impossible to establish a truly laminar flow of air through the room. Any physical objects in the room cause turbulence in the air stream as the air flows past such objects. It is, therefore, highly desirable to design and position such objects so that they produce the least possible turbulence and thus cause the air stream to entrap the fewest possible particles.